Favorite Panties
by WrenClayton
Summary: Careful scientific investigation is the only way to determine which panties Sam looks best in. Warnings: Weecest, Sam is sixteen. Spanking, mild crossdressing.
1. Chapter 1

Dean couldn't decide on his favorite pair. Sam had amassed a rather staggering collection over the years, and there were so many to choose from. Sam had started collecting them years ago, long before that fateful day when his big brother had walked on in him sprawled on the bed, breathless, face red with embarrassment, hard cock in his hand and balls tucked neatly in a pair of lacy pink panties.

Sam had only been collecting more since then, now with Dean's eager encouragement.

"Which should i wear tonight, Dean?"

"Dunno. Pick your favorite, baby boy."

"Which one is _your _favorite?"

Dean raised his eyebrows and shuffled on the bed, folding his arms behind his head and looking his sixteen year old brother up and down. "… Why don't you show 'em off one by one, and I'll decide?"

Sam's grin made Dean think he'd been hoping for that answer.

It didn't make any sense that watching Sam put the panties _on_ was just as hot as watching him take them off. Sam wiggled his cute little butt into the first pair and Dean sat up on the bed to watch the tight, red fabric slide up his brother's fit legs. He grinned when Sam walked over to him, cock already stiffening against the stretchy fabric.

"Here you are gettin' all dolled up for me, Sammy. I'm feeling a little under-dressed."

Sam snorted, brushing his bangs out of his eyes. "Like you could get hotter than a pair of tight jeans and no shirt. That's panties on you, Dean."

Dean patted his thigh. "All right, come on. Lemme get a nice view of those, gotta decide if they're my favorite."

So Sam wriggled his lanky teenage body onto the bed and bent himself over Dean's knee, sticking his ass out to give Dean a nice long look.

This first pair were red with black lace, hugging Sam's round ass so damn well. They always rode right up the crack, showing off each curve, and left half of each cheek bare. Dean couldn't resist stroking his hand over that soft, exposed skin. Or giving that cheek a squeeze. Or a slap. Or another slap. Sam was panting into the sheets by the time Dean rubbed his sore rump and murmured, "Next pair, Sammy."

Then came the white ones, the silky ones with little bows all around and a fake pearl in front. There was something deliciously _virginal _about them, wrapped around Sammy's naughty bits, so modest but so inviting. Dean could tell from Sam's shouts that his spanks were more brutal for that pair.

The floral blue ones were gorgeous. Soft cotton and robin's-egg flowers all over the curves of Sammy's ass. Sam's sore, pink cheeks positively glowed next to that icy blue. Dean kept fiddling with the panties, tugging them down and giving Sam's bare ass a few hard spanks before pulling them back up, adjusting them on Sam's sore ass while Sam whimpered and squirmed.

The black lace ones barely hid anything. Dean could see right through them, see the shadow of Sam's crack under the stretch of the fabric, and when he grabbed one round cheek and spread it, he could see Sam's pink little hole. Dean liked to imagine that his hand left an imprint of the lace on Sam's ass every time he spanked it.

The thong. Oh fuck, the thong. Sam had several, but this one might be Dean's favorite. It was a filthy little string bikini style thing, only the strings were thin strips of _leather. Fucking leather. _Black, shiny leather that looked so damn dirty against Sam's tan skin. Dean had no fucking clue where Sam had found it, but he suspected theft from a strip club. That thin strip that ran right up Sam's crack, it probably brushed against his tight little hole every time he squirmed, teasing the sensitive skin, rubbing rubbing rubbing. The thong left Sam's whole ass bare for Dean's hand, which Dean took full advantage of. Sam gasped and cried out and bucked his hips, rutting his cock against Dean's leg while his big brother spanked him.

Dean's cock was a rock-hard ridge in his jeans and he was more than a little breathless as Sam crawled off his lap and pulled the leather thong down his shaking legs to put on the next pair. Dean swallowed audibly when he saw Sam pick up the next pair and step into them.

"Holy fuck," he choked out. "Fuck."

The soft fabric was bright pink. As Sam pulled it up over his ass, the curly words _Good Girl _could be clearly seen, written across his ass in little pink rhinestones.

Dean flung himself off the bed and knocked about five things off the bedside table before successfully grabbing the lube. Sam gave Dean a puzzled look over his shoulder as he adjusted the panties.

"Uh… No good?" he asked apprehensively.

Dean unzipped his jeans and pulled his cock out, already snapping the lube bottle open with shaking hands. "Bed," he ordered. "Bend over it. Now."

Sam's face went red and his knees seemed to get even weaker. He hurried to do as Dean ordered, wiggling his butt and panting over his shoulder. Dean dropped the open lube bottle on the floor as soon as he'd slicked himself up and splayed his hand over Sam's round, plump ass. He bumped his cock against the words _Good Girl._

"Holy fuck," Dean repeated breathlessly. He tugged the words _Good Girl _aside, revealing Sam's pretty pink little hole, and started pushing his cock in. "Holy _fuck._"


	2. Chapter 2

"Not such a good girl now, are you?"

"A-ah! Dean, Dean, _ahh_!"

"Just wearing those sparkly little panties for show, weren't you? You're not a good girl at all, you're a little slut."

"N-no, I'm a good girl, I promise — "

"Good girls don't bend over for their big brothers, Sammy. They don't get all wet from having big bro's dick in their ass."

"Dean! D-_Dean_!"

"How's it feel, Sammy? Like having a nice, fat cock stuffing you? It looks good, Sam, you look so stretched. Naughty pink hole just full of my dick."

"Oh g-god, d-don't say stuff like that — "

"It's obscene, Sammy. The way you pulled those innocent little panties up over your slutty ass. 'Good girl,' heh. Shoulda said 'come slut.' But we're fixing that now, aren't we?"

"P-please, I'm a good girl, I'm a good girl! Oh g-god, you're so deep — "

"Nhh, takin' the whole thing, baby boy. Nice plump ass pressed against my hips. Good girls can't take a cock this well, you know that. Good girls haven't had_practice_ like you have."

"I c-can't — aah! — p-please, you're gonna make me — "

"Yeah, gonna come with your brother's balls bumping against yours, aren't you?"

"D-Dean!"

"You love being filled up, Sammy, know you do. Getting fucked hard with your panties pulled to the side, like a proper slut. Go on, baby boy, rub that pretty cock for me. Come on my dick like the naughty girl you are. Mmh, f-fuck that's tight… "

"D-Dean, you're g-going so h-hard — "

"Can't help it when you squeeze me like that. So fucking tight around my dick, sweet ass just begging for more — "

"N-no, I'm n-not — "

"Yeah you are, baby, you're a cock-hungry little bitch. Always so eager for me to pull your panties aside and replace them with my dick. Repeat after me: 'I'm a naughty girl, big brother.'"

"N-no, I'm not — I'm a good girl — "

_Smack_

"Try that again, Sam."

"D-Dean, n-not when you're in me! It m-makes me too tight, you're too big — "

_Smack_

_Smack_

"A-a-ah!"

"Say it."

"I… I-I'm a naughty girl, big brother — "

"There you go, now say you love my cock."

_Smack_

_Smack_

"A-ah, l-love your cock, big brother, love the way you fuck me!"

"You gonna come for me, naughty girl?"

"Y-yes, yes — "

_Smack_

"Do it, baby."

_Smack_

"Come with my cock buried inside you."

_Smack_

"You know I'm gonna fill you up with come. Gonna flood you. It's gonna drip out of your used hole, those 'good girl' panties are gonna be come-soaked like they should be — "

"Dean! Dean, I'm — _Dean_! _Oh god keep going keep going, fuck_!"

"Holy f-fuck, you're so damn tight when you come, Sammy — got the best ass in the world, baby brother, just made to swallow up my cock — "

"C-come in me, f-fuckin' come in me!"

"There's my little slut. Nhh, none of this 'good girl' nonsense anymore, huh?"

"Oh god, Dean, please, want your come dripping out of my ass, fill me up — "

"H-holy shit, Sam, you look like such a fuckin' slut, bouncing that little ass on my dick — so damn hungry for it, f-fuck, don't worry, gonna give you what you want, gonna — oh fuck — _fuck _— oh jesus christ _fuck_!"

"God yes, that's it, give me all of it — oh g-god, I can f-feel it, feel your cock twitching, f-fuck — "

"A-ah — oh god, god… Sam… "

"Nhh… m'all sticky… "

"Heh, god yeah, I should hope so. Nnh! … Oh fuck, you should see your little hole, Sammy. All pink and sore and full of come."

"Nhh, Dean… "

"Looks slutty as hell."

"Dean, I think… "

"What is it, Sammy?"

"Heh… I think we found your favorite pair, Dean."


End file.
